Machine for stacking papers into stacks of predetermined count



United States Patent Inventors Leo O. Donahue;

Roy E. Behrens, Highland, California Appl. No. 753,177 Filed Aug. 16, 1968 Patented Dec. 1, 1970 Assignee Graphic Engineers, Inc.

San Bernardino, California a corporation of California MACHINE FOR STACKING PAPERS INTO STACKS [56] References Cited UNITED STATES PATENTS 3,194,127 7/1965 Larsson 93/93 3,327,597 6/1967 Donahue et al 93/93 Primary Examiner-Bernard Stickney Attorney-l-Ierbert E. Kidder ABSTRACT: A first belt conveyor delivers a continuous, overlapping line of papers to a second belt conveyor, which inverts the line and inserts the papers into the bottom of a stack. A photoelectric cell counter counts the papers passing from the first conveyor to the second. When a preselected count is reached, the counter energizes a circuit, stopping the first conveyor and holding the papers thereon until a gap is opened in the line. When the gap reaches a first switch, the first conveyor is caused to resume operation. Upon reaching a second switch, the gap causes a limit stop holding the stack to be released. The stack moves on over a third switch, causing the limit stop to be extended through the gap to start the next stack.

Patented Dec. 1,1915

Sheet l of 5 lzwewroes 150- 0. flown/WE Pay 5 Barge/vs 7 8? 44d! 5 V vb Patmed- Dec. 1,1910

I Sheet Q; g .3 w? J 55 Q MACIIENIE FOR STACKING PAPERS INTO STACKS F PREDE'IERMINEI) COUNT BACKGROUND OF THE INVENTION This invention is an improvement on the apparatus shown and described in our U.S. Pat. Nos. 3,117,500 and 3,327,597, both of which relate to apparatus for conveying papers and stacking them into stacks of predetermined count. In the said patents, a continuous line of overlapping papers travels along a belt conveyor to a stacking station, where the papers are stopped by a limit stop, causing the papers to accumulate into a stack. Means is provided ahead of the stacking station for intercepting the papers periodically so as to open up gaps in the line at intervals such that the number of papers going into each stack in included between gaps. Other means is provided for retracting the limit stop just as the last paper is inserted into each stack, thereby releasing the stack and allowing it to move on. As the stack clears the retracted limit stop, the latter is inserted up through the gap that follows the last paper, and a new stack is started.

The present invention relates to a new and improved form of apparatus for conveying and stacking papers, characterized primarily by: (I) new and improved means for determining how many papers go into each stack; (2) new and improved means for opening up gaps in the continuous line of overlapping papers; and (3) new and improved means for releasing a finished stack and starting a new one.

SUMMARY OF THE INVENTION This invention is a conveying and stacking mechanism for accumulating papers into stacks of preselected count. The mechanism comprises one or more endless belt conveyors, which receive a continuous line of overlapping papers from an associated machine at one end thereof and which travel around a drum rotating about a horizontal axis, to invert the line of papers and to elevate them to a stacking station. At the stacking station, the papers are halted by a retractable stop, and are built into a stackby inserting the papers into the bottom of the stack. The endless belt conveyors include a first conveyor, the delivery end of which is elevated a short distance above the receiving end of a second conveyor, so that the papers are caused to drop downwardly in passing from the first to the second. The line of papers on the endless belt conveyors overlap one another, with the leading edge of each paper resting on the trailing edge of the paper ahead. In dropping from the first conveyor to the second, the trailing edge of each paper flips downwardly as it clears the end of the first conveyor, thereby interrupting a beam of light from a lamp to a photoelectric cell. The photoelectric cell sends an electrical pulse to a counter each time the light beam is interrupted, and when the preselected number of pulses have been received, the counter sends a signal to a relay and simultane ously resets itself to zero. The signal from the counter actuates a circuit causing the papers to be stopped on the first conveyor, while those on the second conveyor continue to move along. This opens up a gap in the line of papers, and as the leading edge of the gap passes a first sensor switch on the second conveyor, it actuates a circuit causing the papers on the first conveyor to resume their travel. A little further along, the gap passes a second sensor switch, causing the retractable stop to be retracted just as the last paper is inserted into the bottom of the stack. The completed stack moves along with the conveyor over the retracted stop, and depresses a third switch, which causes the stop to be extended through the gap following immediately behind the stack, so as to engage the leading edge of the next succeeding paper to start the next stack.

The primary object of the invention is to provide an improved apparatus of the class described, which will form stacks of any desired count, and which is not limited to just a few specific stack counts, as in our previous patents.

Another object of the invention is to provide an apparatus of the class described which is capable of operating at extremely high speeds, with precision and extreme accuracy of count.

A further object of the invention is to provide an apparatus of the class described embodying a counter which counts each paper as it goes past a first point on the conveyor, and upon reaching a preselected count, causes a gap to be opened up in the line of papers traveling on the conveyor; said gap being then utilized to time the actuation of the mechanism whereby the limit stop is retracted when said gap reaches a second point on said conveyor, thereby allowing the completed stack to move on; said limit stop being extended through said gap when the stack passes a switch located beyond the limit stop at a distance substantially equal to the width of the stack.

Still another object of the invention is to provide an apparatus of the class described, which can be programed to built stacks of preselected random count, i.e., each stack having its own count which may be the same or different from the counts of the stacks that precede and follow it. Such programing might be accomplished by magnetic tapes or punched cards, and would be particularly useful for stacking papers according to the requirements of the mailing room, or for distribution to delivery boys according to the needs of their respective routes.

These and other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment thereof,

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a machine embodying the principles of the invention;

FIG. 2 is a top plan view of the same;

FIG. 3 is an enlarged fragmentary sectional view, taken at 3-3 is FIG. 2;

FIG. 4 is a view of a portion of the apparatus shown in FIG. 3, showing the device in paper-engaging position;

FIG. 5 is a fragmentary sectional view, taken at 5-5 in FIG.

FIG. 6 is a schematic diagram, showing the electrical circuit of the apparatus;

FIG. 7 is a fragmentary sectional view, corresponding to FIG. 3, showing another form of the mechanism for halting the papers on the first conveyor and causing them to accumulate into a compact but relatively uniform shingle" while the gap is being opened, whereby the papers are still separate and distinct from one another and can be counted by the photoelectric cell counter when their travel is resumed;

FIG. 8 is a view similar to FIG. 7, showing the mechanism in operation;

FIG. 9 is a sectional view taken at 9-9 in FIG. 7;

FIG. 10 is a fragmentary sectional view, corresponding to FIGS. 3 and 7, showing still another form of the mechanism for halting the papers on the first conveyor and causing them to accumulate into a compact, relatively uniform shingle while the gap is being opened;

FIG. 11 is a view similar to FIG. 10, showing the mechanism in operation; and

FIG. 12 is a circuit diagram, showing the electrical circuit for the embodiment of FIGS. 10 and 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS together with other miscellaneous structural members, including side plates 18 and I9. Lying on top of the two top side members 12 and bridging the space between them is a horizontal table surface 20, which constitutes the loading table.

Mounted in the lower portion of supporting frame 10 and projecting beyond the right-hand end thereof, is a first con veyor 22, the projecting end of which is disposed to receive a continuous line of overlapping, or shingled papers from the final unit of a sheet, or web-fed perfecting press (not shown), or any other machine that delivers sheets in a generally similar manner.

As best shown in FIG. 5, the conveyor 22 comprises two belt conveyor sections 23 and 24 arranged end to end, the former 23 being a short section of conveyor which is adapted to be stopped and started, as will be described presently while the latter 24 runs continuously and discharges its load onto conveyor 23. Both conveyor sections 23 and 24 are carried by laterally spaced parallel side plates 25, having bearings mounted on the inner sides thereof, in which shafts 26, 27 and 28 are journaled. The shafts 26 and 27 of the conveyor section 23 have pulleys 29 mounted thereon, and trained around these pulleys are endless belts 3i Shafts 28 of conveyor section 24 (only one of which appears in FIG. have pulleys 31 mounted thereon, and trained around these pulleys are endless belts 32. Belts 32 of conveyor section 24 are alined with belts 30 of conveyor section 23, and all of the belts, on their upper courses, slide on the top surface of a horizontal sheet metal table 33 extending between side plates 25'. The left-hand ends of side plates 25 are pivoted at 3% to the projecting ends of frame members 116 for vertical swinging movement. Plates 25 are adjustably secured by means of bolts 36, which are passed through one or another of a plurality of vertically spaced holes in end members 114.

Mounted on conveyor 22 adjacent end frame members 14- is a jogger 49 consisting of two laterally space, elongated side plates 41 disposed on opposite sides of the outer belts 32 to conveyor sections 24, and extending generally parallel thereto. Side plates 41 are pivoted at their left-hand ends (as viewed in FIGS, 11 and 5) for horizontal swinging movement, and their right-hand ends are moved rapidly back and forth in the direction transverse to the flow of papers, thereby oscillating the plates about their pivots, and acting to tap any laterally projecting papers back into alinement with the others. Side plates All are adjustable so that they can be spaced apart the width of the papers traveling on the conveyor belts.

At its left-hand end, the short section 23 of first conveyor 22 delivers its load of papers onto a second conveyor 42, consisting of four mounted on a transverse shaft 4%. Shaft 42 is rotatably supported by bearings Sll, and is driven by a variable speed electric motor 52, which is mounted on the frame end between the two bottom side members 13. Motor 52 has an integral speed-reduction gear box 53, the output shaft of which has a sprocket S4 driving a chain 55. Chain 55 is also trained around a driven sprocket 56 on shaft 68.

The endless conveyor belts 44 are trained around four groups of idler pulleys 58, 59, 60 and 61, in addition to pulleys 46, and one course of the conveyor belts is wrapped around one-half the circumference of a horizontal drum 62. The belts 44, where they pass around drum 62, overlie another group of four laterally spaced conveyor belts 64, which also pass around drum 62 and around idler pulleys 65 (FIG. 3). Drum 62 is of relatively large diameter and extends substantially the full width of the frame adjacent the one end thereof. ldlers 65 are much smaller in diameter than drum 62, and the tops of the drum and the idlers are substantially tangent to the plane of the table top 20. in passing from the top of drum 62 to the idlers 65, the belts 64 slide over the top of the table 20.

ldler 65 may be a single roller, or it may consist of a plurality of laterally spaced rollers mounted on a shaft 66, which is rotatably supported at its ends in suitable bearings mounted on the insides of the top frame members 12.

Drum 62 is mounted on a shaft 68, the ends of which are journaled in bearing mounted on frame members 17. Drum 62 is driven by frictional engagement of the conveyor belts 44, which are driven, in turn, by motor 52 through chains 55 and sprockets 54 and S6.

it will be noted in H6. i that idler pulleys 6% are mounted on a shaft 74}, the ends of which are journaled on arms 72. Arms 72 are pivoted at their right-hand ends for swinging movement about the rotational centers of idler pulleys 59, and belts 4A are passed over the tops of idler pulleys 59 and under pulleys 60 in a generally S-shaped path. The free, lefthand ends of arms 72 are connected to a tension spring 7 which pulls downwardly on the outer ends of the arms, thereby taking up any slack in belts 4 5, while permitting them to yield when carrying thick, folded papers around drum 62.

The papers that are delivered onto the receiving end of conveyor 42 are carried around the left-hand side of drum 62 and emerge onto tabletop 2b, where they are stopped and formed into a stack by means of a limit stop 76. Limit stop 76 preferably comprises a bar 78, extending transversely across the frame just beneath the loading table 29. The bar it is attached to one end of a pair of laterally spaced arms 353, the other ends of which are mounted on a sleeve that is free to turn on a shaft 82, extending through the center of the sleeve. Shaft 82 is attached at its ends to the top side members 12. Arms extend generally parallel to conveyor belts as, and the free ends of said arms swing in a vertical plane. Bar 7 8 has fingers 34 projecting upwardly from its top edge, and these fingers project through slots in tabletop 26 between the conveyor belts 64.

During normal stacking operations, limit stop 76, is raised so that fingers 84 stand in the path of papers traveling on the conveyor belts 6 1.1% the papers contact fingers 8 5, they are stopped, and the next succeeding papers is pushed underneath the one above, it, thereby building the stack from the bottom. When the stack reaches the predetermined count of papers, limit stop 76 is lowered, and fingers 84 are retracted below the surface of tabletop 20, allowing the stack to move along the conveyor belts 64 to that portion of the tabletop beyond the limit stop. As the stack clears limit stop '76, it is followed by a gap in the line of papers, and limit stop fingers $4 are raised through this gap so as to engage the leading edge of the next succeeding paper.

Limit stop 76 is spring-loaded to its extended position by means of a spring 85, one end of which is anchored to a bracket 86 and the other end attached to an arm 67 projecting downwardly from the underside of an adjacent pivot shaft 82. Spring exerts a counterclockwise torque on arms 8t), tending to keep fingers 34 in the elevated position.

The limit stop is retracted by means of a solenoid 88, the armature 39 of which is connected by a link 9th to one of the arms Sll. Solenoid 88 is mounted on a crossbar 91, which extends between, and is fixed to, the side plates 18 and 19.

The heart of this invention lies in the novel means used for building stacks of any desired count. This is done by means of a unique arrangement which counts the papers as they are transferred from the first conveyor 22 to the second conveyor 42, and when a preselected count has been reached, the output end of this conveyor 22 (in this case, the short conveyor section 23) is stopped momentarily, while conveyor 42 continues to run. This causes the papers on conveyor 42 to pull away from those on conveyor 22, thereby opening up a gap in the line of overlapping papers. As the leading edge of the gap advances past a first point along the length of conveyor 42, the passage of the gap is detected by a feeler which actuates a switch causing conveyor 22 to resume operation. The gap is thus used to time the operation of limit stop 76, as will be described presently.

The papers are counted by means of a photoelectric cell unit 92 and lamp unit 93, mounted on opposite sides of the frame ill in the area between the delivery end of short section 23 of conveyor 22 and the receiving end of conveyor 42. As best shown in FIG. 3, the delivery end of conveyor section 23 is elevated somewhat above the receiving end of conveyor 42, and therefore, the papers must drop down to the lower elevation. Since the leading edge of each paper overlies the paper ahead, the leading edges of the papers are supported, and tend to arch over from conveyor section 23 to conveyor 42 in a more-or-less smooth curve. However, the trailing edges of the papers are not so supported, and tend to flip'downwardly as each trailing edge clears the end of conveyor 23. As the trailing edge of the paper flips downwardly, it momentarily interrupts a beam of light from lamp 93 to photoelectric cell 92, causing the latter to put out a signal in the form of a momentary pulse of electrical current.

Each of the photoelectric cell and lamp units 92, 93, is adjustably mounted on a mounting plate 94 (FIG. 3), which is bolted to one edge of the, adjoining side plate 10, 19. The plate 941 has a horizontal slot 95 provided therein, through which a mounting bolt 96 passes, said bolt being slidable along the slot to permit adjusting the position of said photoelectric cell unit to the spot where it is most responsive to the interruption of the light beam from lamp 93 by the downwardly flipping papers.

The signals from the photoelectric cell 92 are fed into a high speed counter 97 of the type which indicates the number of papers counted by visual and/or electrical readout means and which, after recording a preselected number of papers (25, for example), sends a transfer, or output pulse, to a normallyopen relay switch 98. At the same time, the counter resets itself to zero, and starts a new count. The counter is adjustable from to 999 (or any number within the range of the counter readout), and its operating mechanism may be of the electromechanical type shown and described in US. Pat. No. 3,238,359, or it may be an electronic counter using a solidstate circuit. The counter 97 is standard equipment available on the market, and it details from no part of this invention.

For purposes of illustration, the counter 97 may be considered to be of the electromechanical type, such as that shown in the aforementioned patent, to which reference may be had for details of its construction and mode of operation. As described in that patent, the basic components of counters of this type are: a number wheel, and electrically actuated stepping mechanism, and switching mechanism for producing a transfer pulse, as well as for resetting the number wheel to its initial starting, or zero position.

The counter 97 is mounted on the underside of tabletop 20 and, as shown in FIG, 6, the electrical signals from the photoelectric cell 92 are transmitted to the counter by wires 99. The transfer, or output pulse, put out by the counter upon reaching the preselected count, energizes the electromagnet coil 100 of the relay switch 90 which, in FIG. 6, is shown as an integral part of counter 97. The relay switch 90 is connected by wires 101 and 102 to one side L1 of the electrical line. Switch 98 is also connected by a wire 103 to the electromagnet coil 104 of relay switch 105.

Relay switch 105 has two pairs of contacts 106, 107 and 108, 109, which are selectively closed by a conductor bar 110 on the armature. When the coil 104 of relay switch 105 is deenergized, the armature falls by gravity (or spring tension) to the bottom position, where the conductor bar 110 bridges contacts 108, 109. When the relay switch is energized, the armature is pulled upwardly by magnetic force, closing the conductor bar 110 against contacts 106, 107. The other end of the electromagnet coil 104 is connected by normally-closed switch 111 and wire 112 to the other side L2 of the line.

Relay switch 105 is of the holding type, i.e., it continues to energize its magnet 104 even after switch 98 has opened. This is accomplished by means of a second conductor bar 113 on the armature of relay 105, which closes two contacts 114 and 115 when the relay coil is energized. Contact 115 is connected to a wire 116, which goes to L1; while contact 114 is connected to coil 104- and thence to L2. Thus a separate shunt circuit is closed by relay 105 when coil 104 is energized, sending current from L2 to col] 104 to keep the latter energized until switch 111 is opened.

Switch 111 is located under conveyor 42 about the same distance beyond the receiving end of the conveyor as the width of one of the papers. The switch is adjustably mounted on a mounting plate 117 having an elongated horizontal slot 118 provided therein, through which the mounting bolt passes.

Extending upwardly at an angle from the switch 111 is a feeler arm 120 having a contact wheel 121 journaled on the outer end thereof. Feeler arm 120 is spring-loaded upwardly, and contact wheel 121 thus bears upwardly against the underside of the line of papers. The pressure of the papers against contact wheel 121 depresses the feeler arm 120, holding the switch 111 closed. However, when a gap comes along, feeler arm 120 is no longer held down by the papers, and rises above the top surface of the belts 44, thereby opening the switch 111. When this happens, the relay switch 105 is deenergized, and its armature falls to the lower position, closing contacts 100 and 109.

Contacts 100, 109 carry current to a solenoid 122, the other end of which is connected by wire 112 to L2. When contacts 108, 109 are closed, solenoid 122 is energized. The function of solenoid 122 will be explained in a moment.

Contact 108 is also connected by a wire 124 and full-wave rectifier 125 to a magnetic clutch 126, which is a part of the power transmission means for driving the short conveyor section 23 of first conveyor 22. As mentioned earlier, motor 52 drives shaft 48, which drives the second conveyor 412. Mounted on shaft 48 is a sprocket 128 (see FIG. 5), which drives a chain 129 trained around a second sprocket 130 mounted on the power input member 132 of the clutch 126. Clutch 126 is mounted on the inside surface of one of the side plates 25, and its power output member (not shown) is connected to a jackshaft 13d.

Jackshaft 134 extends across the width of the conveyor frame, and its other, end is supported in an electric brake 136. Brake 136 is mounted on the inside of the other side plate 25. Mounted on the jackshaft 134 adjacent the brake 136 is a sprocket 138, which drives a chain 140 trained around a second sprocket 142, that is mounted on conveyor drive shaft 26. As shown in FIG. 6, the terminals of brake 136 are connected to a full-wave rectifier 146, which, in turn, is con nected by a wire 147 to contact 106, so that the brake is energized when contacts 106, 107 are closed by conductor bar 113. Thus the short conveyor section 23 is driven by jackshaft 134 when clutch 126 is energized and brake 136 is deenergized, and is stopped thereby when clutch 126 is released and brake 136 is energized. Inasmuch as the clutch 126 is engaged when contacts 108, 109 are closed, and brake 136 is deenergized when contacts 106, 107 are opened, it will be evident that the conveyor section 23 is driven when relay switch 105 is deenergized, and is stopped when the relay is energized by a transfer pulse received from the counter 97.

Conveyor section 24, on the other hand, is driven continuously, and without being interrupted by clutch 126 and brake 136, from drive shaft 48 to which it is connected by sprockets 143, 14 i and chain 145.

Each time the short conveyor section 23 is stopped, papers continue to arrive from the still-running conveyor section 24, and these oncoming papers tend to pile up on the stopped delivery end of the conveyor. To prevent the papers from piling up into a bulky, unmanageable pile in which they cannot be separated from one another and individually counted by the photoelectric cell 92, we provide a shoe 1 18 having an upwardly curved end on the incoming side. The said upwardly curved end is suspended from the tabletop 20 by a chain 150. The other end of the shoe 148 is also upturned at 152 and is connected to the outer end of an arm 15 1. Arm 154 is mounted on a transverse shaft 156, the ends of which are supported by uprights 158. Projecting from the other side of shaft 156 is a much shorter arm 160, which is connected by a link 1162 to the armature of solenoid 122.

When solenoid 122 is deenergized, shoe 168 drops by gravity down onto the line'of papers on conveyor belts 32, and as the papers crowd forwardly'under the pressure of the oncoming stream, they tend to bunch up in a forwardly tapered, uniform shingle under the shoe 100, as shown in FIG. 4. This closed-up shingle of papers still separates the papers from one another and allows the trailing edge of each paper to flip down through the light beam of lamp 93, causing the photoelectric cell 92 to register for each paper.

The moment the short conveyor section 23 stops, the onwardly moving stream of papers on conveyor 32 pulls away from the stopped papers on conveyor 23, opening a gap in the line of papers which almost immediately uncovers and releases the feeler arm 120, causing switch ill to open and thereby causing conveyor section 23 to resume operation.

The circuit comprising relay switch 105, switch ill, solenoid 122, clutch 126 and brake 136, have to do with the mechanism for opening up a gap in the line of papers, and this circuit is designated generally by the reference numeral 164, and is referred to in the claims as the first circuit means. A second circuit 166, referred to in the claims as second circuit means will now be described.

The second circuit 166 comprises solenoid 88, a relay switch 16%, a normally-open switch 17d, and a normallyclosed switch 172. Relay switch 168 is normally open, and when energized, closes the circuit to solenoid 88. Relay switch 168 is energized by momentarily closing switch 170, which sends current through the relay coil. Relay switch 168 has a first conductor bar T173 that bridges contacts 174 and l75, thereby completing the circuit to solenoid 88; and a second conductor bar 176 that bridges contacts l7? and 178, thereby completing a shunt circuit supplying current to the coil to energize the same. When switch 168 is closed, current from the closed contacts 177, 173 supplies energy for the coil, which thus remains energized until switch 172 is opened. Opening switch 1172 deenergizes the relay coil, and causes the relay switch to open.

Switch lifl is mounted on the underside of the tabletop 20, and has an upwardly spring-loaded feeler arm 18% with a contact roller 182 on the outer end thereof. Contact roller 182 rides on the underside of the papers traveling on the conveyor belts 64, and as long as there are papers pressing the feeler arm downwardly, the switch 170 remains open. However, when a gap in the line passes over roller 1132, feeler arm 180 springs upwardly, thereby causing switch 174i to close. Closing switch 170 causes the solenoid 88 to be energized, which retracts the limit stop 76 to allow the completed stack to move on past the fingers 3.

As the stack moves clear of the fingers tll, the leading edge of the stack slides over and presses downwardly on the contact roller the of switch H72, depressing its feeler arm 136 and causing switch 172 to open. Opening switch 372 deenergizes the relay switch 168, which causes the circuit to solenoid $8 to be opened. Solenoid 3%} is thus deenergized, thereby allowing spring 85 to extend the limit stop 76 to engage the papers following the gap. Both of the switches 17% and 172 are adjustably mounted on mounting plates 188, so that they can be shifted one way or the other, according to the dimensions of the papers being handled.

FlGS. 7, 8 and 9 show another embodiment of the mechanism for stopping the line of overlapping papers so as to open up a gap therein, and also for accumulating the oncoming papers into a forwardly tapered, uniform shingle, so that they can be counted by the photoelectric cell when travel is resumed. In this form of the invention, the conveyor 22' comprises a single belt conveyor section, consisting of three endless belts 190, which pass around pulleys 1192 mounted on a transverse shaft M4; the top course of the belts sliding on top of a sheet metal panel 196 fixed to the top edges of side plates 25' and extending therebetween.

Shaft we is rotatably supported at its ends in bearings W8 mounted on side plates 25', and is driven from a jackshaft 134' (see FIG. 7). Jackshaft 134- is located about midway between shafts 4t; and 11%, and a short distance below them, as shown in FIG. 7. Mounted on one end ofjackshaft 1134 is a sprocket Zilll driven by a chain 2&2, which is also trained around sprocket 128' on shaft 43. Jackshaft 1314' is thus driven at all times from shaft 48, which is continuously driven, in turn, by motor 52 and driven chain 55.

Near its other end, jaclrshaft 3134' has another sprocket 204, which drives chain 2%. Chain 2% is trained around a sprocket 2%, which is fixed to shaft i9 at one end thereof, and also around another sprocket 210 mounted on the rotatable input member 2112 of clutch llZd'. Clutch 126' is mounted on one of the side plates 25', and its output member (not shown) is connected to one end of a shaft 211%, upon which a roller 216 is mounted. Shaft 214 is in the same horizontal plane as shaft 194, and parallel thereto, and the top of roller 216 is in the same horizontal plane as the top of rollers The other end of shaft 214 is connected to brake 1136, which is mounted on the other side plate 25'.

Conveyor belts are driven continuously from the jackshaft 134' by chain 206 and sprockets 2%, 208. Roller 216 is driven at the same peripheral speed as the belts 1% when clutch 12s is engaged and brake U6 is released. However, when clutch 126 is disengaged and brake F1336 is applied, roller 2% is stopped. As the papers leave the belts 1%, they pass immediately onto the roller 216, which continues to drive them at the same speed as the belts. Thus, roller 216 may be considered as an integral part of the conveyor 22.

Thepapers are held down against the roller 216 by a pro"- sure wheel 2118, which turns on an axle 2230 carried at the outer end of an arm 222. The other end of arm 222 is pivotally supported for vertical swinging movement on a transverse shaft 224. Shaft 224 extends across the width of the conveyor, about a foot or so above the belts 1190, and its ends are fixed to upstanding posts 226, which are bolted to the outer sides of plates 25. Pressure wheel 218 rides on top of the line of overlapping papers, and its weight holds the papers down against the roller M6 in good frictional engagement therewith. Thus, when the roller 2 26 is stopped abruptly by the brake 1136', the papers are stopped almost instantaneously; and when the brake is released and clutch 126' is again engaged, the papers accelerate almost instantaneously up to full speed, with no appreciable lag. As the papers are stopped by roller 2%, those papers that have cleared the roller and are resting on the belts 434 of conveyor 42 continue to move along, thereby opening up a gap in the line of papers, as in the preceding embodiment.

The papers on conveyor 22' are transported continuously up to the roller 2116 by the constantly advancing belts 1%, and when the roller is stopped, the papers tend to accumulate and to pile up. To accumulate the overlapping papers in a uniform, forwardly tapering shingle so that their downwardly flipping trailing edges will produce separate and distinct interruptions in the beam of light from lamp 93' to photoelectric cell 92, whereby the latter can count them, the papers are engaged from below by a pair of members 22%, that raise up to form an inclined ramp, up which the papers are pushed by the pressure of the papers behind. Each of the members 228 is a narrow strap of steel, which normally rests on the sheet metal panel 196 between the belts 1941! and parallel thereto. The upstream end (i.e., the right-hand end in FIGS. 7, 8 and 9) is bent downwardly at right angles, and passes down through a hole 230 in panel 1%; and its lower extremity passes through a diametric slot in a transverse shaft 232.

Shaft 232 is supported at its ends for oscillating movement on the side plates 25, and fixed to one end thereof is a downwardly projecting arm 234, the lower end of which is connected by a rod 236 to the armature 238 of a solenoid 240. When solenoid 240 is deenergized, members 228 lie flat on panel 1%; and when the solenoid is energized, the members 228 are tilted upwardly, as shown in FIG. 8, forming an inclined ramp up which the papers are pushed by the crowding action of the papers behind. The inclined ramp formed by members 22% lifts the papers off the belts 190 and at the same time exerts frictional resistance to forward movement of the line of papers. Thus, as the line of papers carried by belts 1% continues to crowd papers up the inclined ramp, the papers tend to close together-and shorten the amount of overlap, without piling up into an unmanageable stack.

inasmuch as solenoid 24GB constitutes the means for opening up a gap in the line of papers, it corresponds to solenoid 122 of the embodiment in FIGS. 1-6, and-receives its current from switch 105. However, solenoid 24h differs from solenoid M32 in the respect that the former is energized when brake 136 is actuated and clutch 126' is released, whereas the latter is energized when brake 136 is released and clutch 126 is engaged. Thus, solenoid 260 is connected to contact 106 of switch 105, instead of to contact 108, as in FIG. 6, and solenoid 266 is therefore energized when relay switch 165 is energized.

It will be noted that the downstream end (i.e., the lefthand end in FIGS. 7, 8 and 9) of members 228 are hinged at 242, so that the outer end portion thereof folds downwardly. The purpose of this is to prevent the end of member 223 from coming up over the trailing edge of the paper that is stopped directly on roll 216, in which case the end of member 226 might pinch the paper against the roll when the member 223 is dropped by solenoid 240, thereby causing a jam. By hinging the ends of members 228, the said ends slope downwardly and forwardly from the hinge when the members are inclined upwardly, as in FIG. 8, and as the members 228 swing downwardly, their hinged ends swing upwardly and forwardly .to the horizontal position shown in FIG. 7.

FIGS. 10, 11 and 12 show still another embodiment of the mechanism for stopping the line of overlapping papers so as to open up a gap therein, and at the same time accumulating the oncoming papers into a forwardly tapered, uniform shingle. In this embodiment of the invention, the first conveyor is designated by the reference numeral 22" and comprises a single belt conveyor section, consisting of three or four laterally spaced, endless belts 256, which pass around pulleys 252 (only one of which can be seen in FIGS. and 11), and a small-diameter idler pulley 253, the latter being located above and to the left of pulley 252. The purpose of idler pulley 253 is to provide a relatively sharp, angular corner over which the papers drop, for the purpose of getting a more accurate, instantly-responsive cutoff when the predetermined count has been reached. The top surface and left-hand sides of idler pulley 253 are tangent to the top surface and left-hand sides, respectively, of pulley 252, and the line of papers passes first over the top of pulley 252 and then over pulley 253 before dropping down onto belt conveyor 42. Pulleys 252 are mounted on transverse shafts 254, the ends of which are journaled in bearings on the side plates 25". The top courses of the belts 250 slide on top of a horizontal sheet metal panel 256, which is fixed to the upper edges of side plates 25" and extends therebetween.

Shaft 254 is driven directly from shaft 458 by a chain 258, which is trained around sprockets 261) and 262. In this embodiment of the invention, there is no clutch or brake in the power transmission from shaft 48 to pulley 252, and conveyor 22" runs continuously and without interruption, as long as conveyor 62 is running.

The papers are stopped just ahead of the photoelectric cell 92 by means of lifters 264, which cooperate with overhead blocking members 266. The lifters 264 may be flat bars or plates, which normally lie on the panel 256 between belts 250 and parallel thereto. The downstream ends of the lifters (i.e., their left-hand ends, as viewed in FIGS. 10 and 11), lie in the vertical plane of idler pulley 253, while their upstream ends, or right-hand ends, are attached to a transverse rockshaft 268, which is supported at its ends for oscillatory movement. Fixed to one end of rockshaft 268 and projecting downwardly therefrom is an arm 270, the free end of which is connected by a link 272 to the armature 274 of an electromagnet 276. Also fixed to rockshaft 268 on one side of the conveyor 22 is a second arm 278, which is connected by a link 286 to an arm 282 on a second rockshaft 264. Rockshaft 284 extends transversely across the conveyor 22", about 6 inches (more or less) above the belts 250, and is rotatably supported at its ends on upstanding posts 286, which are fixed to the side plates 25" of the conveyor support frame. Blocking members 266 are fixed to rockshaft 284i and extend downstream" therefrom (i.e., to the left in FIGS. 16 and 11), directly above their corresponding lifters 264. The blocking members 266 are likewise in the form of bars or plates, similar to lifters 264 but only about one-third as long as the latter, and their left hands lie directly above the left-hand ends of the lifters.

by link 280 Rockshaft 284 is rocked in the counterclockwise direction at the same time that rockshaft 263 is rocked in the clockwise direction, and the outer ends of lifters 264 and blocking members 266 therefore come together like pincers, as shown in FIG. 11. As the lifters 264 swing up to the raised position of FIG. 11, the papers directly over them are lifted up from belts 250 and lose driving contact therewith. However, the oncoming papers from behind push the papers ahead of them up the inclined ramp formed by the raised lifters, crowding them into the converging, forwardly tapered space defined between lifters 264 and blocking members 266. The papers thus crowded into the forwardly tapered space are therefore shingled, but are compacted together somewhat, as shown in the drawings. Lifters 264 are raised only momentarily, and the crowding together of the shingled papers is therefore only a momentary thing, involving perhaps a dozen or so papers.

Due to the relatively sharp, angular dropoff corner provided by the small-diameter idler pulley 253, and the fact that the left-hand ends of lifters 264 extend out to the vertical plane of the idler pulley, the line of papers is lifted almost instantly after the last papers of the predetermined count has dropped through the light beam going to the photoelectric cell 92, so that the left-hand ends of the lifters 264 and blocking members 266 close together on the next succeeding paper at its midpoint, as shown in FIG. 11. The line of papers on belt conveyor 42 continues to move along, while those papers intercepted by the lifters and blocking members are halted, and a gap is thus opened up between the trailing edge of the moving papers and the leading edge of the halted papers. When the trailing edge of the moving papers reaches switch 111, the circuit to the solenoid 276 is opened, allowing lifters 264 to drop back onto the panel 256, and blocking members 266 to be raised. The dropping of lifters 264 and raising of blocking members 266 is aided by a spring 290, which is connected to arm 270 and opposes the pull of solenoid 276. Dropping the papers down onto belts 250 causes them to resume their travel with the belts.

The forwardly tapered, wedgelike formation of the group of papers forming the leading edge of the new batch of papers leaving lifters 264 makes -a slightly crowded-together shingle, but there is still sufficient lengthwise separation between papers so that their respective trailing edges flip downwardly through the beam of light from lamp 93 in separate and distinct interruptions of the beam, enabling the photoelectric cell counter to register each one as it passes.

The electrical circuit for controlling the operation of this embodiment of the invention is shown in FIG. 12. Most of the circuit is the same as in the circuit of FIG. 6, and components which are the counterparts of similar components in the latter circuit have been given the same reference numerals, and will not be described again. As in the previously described embodiment, the circuit consists of a first circuit 164', which has to do with the mechanism for opening up gaps in the line of papers, and a second circuit 166, which has to do with the operation of limit stop '76. The second circuit 166' is identical in every respect to the circuit 166 of FIG. 6, and will not be described further.

First circuit 164 is generally similar to circuit 164, but with the following differences: Solenoid 276 corresponds to solenoid 122 of FIG. 6, but is normally deenergized. There is no brake 136 or clutch 126 in circuit 164', and therefore contacts 106 and 107' are used to close the circuit to solenoid 276 when relay electromagnet 194 is energized. Contacts 108 and 109 of circuit 164 in FIG. 6 have been eliminated, and contact 106' is connected to solenoid 276 by conductor 147'.

The operation of circuits 1641- and 166 in FIG. 12 is essentially the same as the operation of circuits 164 and 166 of FIG. 6. When counter 97 sends a pulse of current to relay 105, the latter closes contacts 106', I07 and contacts 114, 115. Current passing through contacts 106', 107 energizes solenoid 276 until the holding circuit of relay is broken by the opening of switch 111.

lil

While we have shown and described in considerable detail what we believe to be the preferred form of our invention, it will be clear to those skilled in the art that various changes may be made in the structure of the apparatus without departing from the scope of the claims that follow. F or example, the photoelectric cell and lamp are just one form of sensing means for detecting the passage of each paper from the first conveyor 22 to second conveyor 32 in counting the papers, and other types of sensing means could be used in their places. bther means could be used for opening up a gap in the line of papers besides the arrangement shown in FIGS. 4, 8 and it), and other sensing means could be used to detect the passage of the gap at two points, instead of switches llll and 186), with their respective feeler arms and contact wheels. Moreover, switches res and 168 could be of the mechanical latching type, with each having two separate coils for causing the switch to close one set of contacts or the other, instead of the holding coil arrangement shown in FIGS. 6 and 12.

In the claims, the term papers is intended to include any flexible, sheet-like material capable of being handled by a machine of this class, including plastic sheets, hardback covers for books, etc. Some of the other terms used in the claims refer to components identified as follows in the illustrated embodiments: The term first sensing means refers to the photoelectric cell 92 and lamp unit 93; the limitation means actuated by said pulse of current from said counter for opening up a gap in said line of overlapping papers on said conveyor means refers to circuit 164, with its solenoid 122, brake 126, clutch 13d and associated feeler arm 120 and contact wheel 121 (or alternatively, to circuit 164' with its solenoid 276); the limitation means actuated by said second sensing means" refers to feeler arm 120 and contact wheel 121; the limitation third sensing means refers to feeler arm W4 and Contact wheel 176; the limitation means actuated by said third sensing means refers to switch 176; and the limita tion fourth sensing means refers to feeler arm 186, contact wheel E841 and switch 172. The terms used in the claims are not restricted to the specific devices mentioned above, but might take various other forms.

We claim:

1. Apparatus for conveying papers received from a machine to a stacking station where said papers are accumulated into stacks of a predetermined count, said apparatus comprising:

conveyor means disposed to receive a continuous line of overlapping papers from said machine and operable to transport said papers to said stacking station;

limit stop means disposed to engage the leading edges of said papers to halt the papers at said stacking station, succeeding papers being inserted into the stack at the bottom thereof, and said limit stop means being movable between extended and retracted positions;

a counter having first sensing means for detecting the passage of each paper along said conveyor means, said counter being operable to deliver a pulse of current when a predetermined count has been reached;

means actuated by said pulse of current from said counter for halting the travel of said line of papers along said conveyor means so as to open up a gap in said line of overlapping papers;

second sensing means for detecting the passage of the leading edge of said gap past a first point on said conveyor means;

means actuated by said second sensing means for causing said halted line of papers to resume its travel along said conveyor means;

third sensing means for detecting the passage of said gap past a second point on said conveyor means;

means actuated by said third sensing means for retracting said limit stop means when said gap passes said second point, thereby allowing said stack to move on; and

fourth sensing means for detecting the passage of said stack past a third point beyond said limit stop means, said fourth sensing means being operable to cause said limit stop means to be extended through said gap when said stack reaches said third point.

2. The apparatus of claim il, wherein said conveyor means includes:

a first belt conveyor section which discharges said line of papers onto a second belt conveyor section;

the delivery end of said first conveyor section being elevated above the receiving end of said second conveyor section, whereby the trailing edges of said papers are caused to flip downwardly as each paper clears the delivery end of said first conveyor section; and

said first sensing means of said counter comprises a lamp and a photoelectric cell disposed so that the beam of light from said lamp to said photoelectric cell is interrupted by the downward flipping of the trailing edges of said papers as they drop from said first conveyor section to said second conveyor section.

3. The apparatus of claim ll, wherein said conveyor means includes a rotatable member connected by transmission means to a driving motor:

said means for halting the travel of said line of papers including a clutch serially disposed between said driving motor and said rotatable member, and a brake connected to said rotatable member;

said means actuated by said pulse of current from said counter being operable to disengage said clutch and apply said brake when a predetermined count has been reached; and

said means actuated by said second sensing means being operable to engage said clutch and release said brake.

4. In an apparatus for conveying papers received from a machine to a stacking station where said papers are accumulated into stacks of a predetermined count, said apparatus including a first conveyor disposed to receive a continuous line of overlapping papers from said machine; a second conveyor disposed to receive said line of papers from said first conveyor; motor means operatively connected to said second conveyor to drive the same; power transmission means connecting said first conveyor to said motor means; a rotating drum cooperating with said second conveyor to elevate and invert said line of overlapping papers; and a limit stop movable between a retracted position and an extended position wherein the leading edges of the papers are engaged as they are delivered to said stacking station, thereby stopping said papers and accumulating them into a stack, said papers being inserted into the bottom of the stack; the improvement comprising:

a counter, including sensing means for detecting the transfer of each of said papers from the delivery end of said first conveyor to the receiving end of said second conveyor, said counter being operable to deliver an electrical signal when a predetermined number of papers has been counted;

first circuit means actuated by said electrical signal from said counter for stopping the delivery of papers from said first conveyor to said second conveyor, while said second conveyor continues to advance the line of papers carried thereon until a gap has been opened therein;

said first circuit means including a first switch having a first feeler engaging the undersides of the papers on said second conveyor a short distance beyond the receiving end thereof, said first feeler being depressed by said papers, and being released when said gap passes over;

said first switch being operable, when said feeler is released,

to activate said first circuit means so as to cause resumption of the delivery of papers from said first conveyor to said second conveyor;

second circuit means operable to extend and retract said. limit stop, said second circuit means including a second switch having a second feeler engaging the undersides oi" the papers a short distance ahead of said limit stop, and a third switch having a third feeler engaging the undersides of the papers beyond said limit stop;

said second feeler being depressed by said papers, and being released when said gap passes over; said second switch being operable, when said second feeler is released, to activate said second circuit means so as to cause said limit stop to be retracted; and

saidthird feeler being normally elevated above said second conveyor, and being depressed by a stack of papers moving over the same after said s'tack has been released by said limit stop, said third switch being operable, when said third feeler is depressed, to activate said second circuit means so as to cause said limit stop to be extended.

5. Apparatus as set forth in claim 4, wherein said limit stop is spring-loaded to the extended position, and said second circuit means includes a solenoid which is connected to said limit stop to retract the same when said solenoid is energized:

said second switch being operable to close the circuit to said solenoid so as to energize the same when said second feeler is released; and

said third switch being operable to open the circuit to said solenoid so as to deenergize the same when said third feeler is depressed.

6. Apparatus as set forth in claim 4, wherein said first conveyor includes a rotating drive member, and said power transmission means includes an electrically actuated clutch and an electrically actuated brake, both connected to said rotating drive member; said first circuit means including a relay switch which remains energized after a momentary pulse of current through the coil thereof, said relay switch being operable, when energized, to open the circuit to said clutch and to close the circuit to said brake; said first switch being operable, when said first feeler is released, to open the circuit to said relay switch, thereby deenergizing the same, causing the circuit to said clutch to be closed, and the circuit to said brake to be opened.

7. The apparatus of claim 6, in which there is a member located adjacent the delivery end of said first conveyor and movable between a first position clear of said papers, and a second position engaging said papers in a manner whereby the last paper at the delivery end of said first conveyor is stopped and forward movement of succeeding papers is yieldingly resisted, thereby allowing the papers to crowd together in a forwardly tapered, uniform shingle as the papers continue to be fed onto said first conveyor while the same is stopped said member being normally maintained in said first position, and being moved to said second position only when said clutch is disengaged and said brake is applied.

3. The apparatus of claim 7, in which said member is yieldingly urged toward said second position, said member having a forwardly and downwardly inclined contact surface engaging said papers from above, said papers being crowded forwardly to fill the tapered space between said inclined contact surface and said first conveyor; a solenoid connected to said member and operable, when energized, to hold said member in said first position; and said solenoid being deenergized when said clutch is disengaged and said brake is applied, thereby allowing said member to move to said second position 9. The apparatus of claim 7, in which said member is disposed beneath said papers and extends parallel to the line of travel thereof:

said member having one end adjacent the delivery end of said first conveyor and its other end upstream of said one end;

said member being tiltable upwardly about said other end, engaging said papers from below and raising them clear of said conveyor; and

said member forming an inclined ramp up which the papers are crowded by the pressure of oncoming papers behind.

10. The apparatus of claim 9, in which said rotating drive member of said first conveyor comprises:

a horizontal roller at the delivery end of the conveyor extending transverse to the direction of travel of said papers;

means engaging said papers from above and pressing them downwardlyv against said roller so as to maintain firm frictional engagement between the papers and the roller;

said member being hinged adjacent said one end, whereby the portion of said member downstream of the hinge is inclined downwardly toward said roller when said member is tilted upwardly about said other end;

a solenoid operatively connected to said member to tilt the same upwardly about said other end when the solenoid is energized; and

circuit means for energizing said solenoid when said brake is actuated and said clutch is released.

11. The apparatus of claim ll, wherein said means for halting the travel of said line of papers along said conveyor means comprises:

lifters disposed beneath said line of papers and parallel thereto, said lifters being normally clear of said papers and having downstream ends that terminate immediately ahead of said first sensing means of said counter;

blocking means positioned above said lifters and cooperating therewith to halt said line of papers on said conveyor means; said blocking means and said lifters'being movable between a first position in which both of them are clear of said papers and a second position in which said lifters are inclined upwardly from their upstream ends and said blocking means converge forwardly with respect to said inclined lifters;

means responsive to said pulse of current from said counter for simultaneously moving said lifters and said blocking means from said first position to said second position;

said upwardly inclined lifters raising the papers thereon clear of said conveyor means and forming an inclined ramp up which the papers are pushed by the pressure of oncoming papers from behind; and

said blocking means and said lifters coacting, when in said second position, to clamp together on the top and bottom sides of the next paper beyond the one that triggered said counter, and said blocking means and lifters cooperating to define a forwardly converging tapered space into which the papers are crowded by pressure from behind, said forwardly converging, tapered space forming said papers on said lifters into a compact shingle which can be counted by said counter; said blocking means and said lifters being simultaneously restored to said first position when said second sensing means detects the passage of the leading edge of said gap past said first point on said conveyor means, thereby dropping said papers back onto said conveyor means and releasing them so that the papers may resume their travel thereon.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,543,651 Dated December 1, 1971 Inventor-(s) Leo O. Donahue and Roy E. Behrens It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the specification, column 2, line 16, "programed" should read --programmed--; line 17, "built" should read --bui1d--; line "is" should read --in- Column 3, line 46, after "four" should re --latera.l1y spaced conveyor belts 44, which are trained around pull Signed and sealed this 11th day of May 1971.

(SEAL) Attest:

EDWARD M.FIETCHER,JR. WILLIAM E. SCHUYLER, Attesting Officer Commissioner of Patent 

